Wrench.



No. 795,428. PATENTED JULY 25, 1905. F. G. CORNELL.

WRENCH.

APPLIOATION nun JAN. 19. 1905.

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UNITED STATES PATEN OFFICE.

FRANK (3r. CORNELL, OF LOUISVILLE, KENTUCKY, ASSIGNOR OF ONE- FOURTH TO AUGUSTUS E. WVILLSON, OF LOUISVILLE, KENTUCKY.

WRENCH.

Specification of Letters Patent.

Patented July 25, 1905.

Application filed January 19, 1905. Serial No. 241,831.

To all whom it may concern.-

Be itknown that I, FRANK G. CORNELL, a citizen of the United States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented certain new and useful Improvements in renches; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the letters of reference marked thereon.

This invention relates to improvements in wrenches primarily adapted for grasping and turning pipe or other cylindrical objects, although it may be utilized for cooperation with square or irregularly-shaped surfaces, thus adapting the wrench for universal use wherever a wrench having relatively movable jaws adapted to be closed on the article gripped thereto and turned by a single movement of the handle in one direction could be used. More specifically the wrench is of that type wherein the jaws have a relatively wide range of movement to adapt it for use on pipe or other articles of widely different diameters; and it is one of the obj ects of the invention to provide a structure wherein the gripping power is made ample and substantially uniform throughout the whole range of movement without creating strains in the structure such as will bend or rupture the same when heavy duty is im posed on the wrench.

A further object of the invention is to provide a structure wherein the crushing pressure exerted on the object will be so modified and regulated as to be in accord with the torque required to rotate the object, whereby the danger of crushing hollow objects is reduced to the minimum.

A further object of the invention is to provide a structure which shall be of simple design and the elements of which may be simple castings adapted to fit and work together without the necessity of being machined or on which the machine-work may be reduced to the minimum.

The invention consists in certain novel details of construction and combinations and arrangements of parts, all as will be now described, and pointed out particularly in the appended claims.

Referring to the accompanying drawings,

Figure 1 is a side elevation of a wrench embodying'the present improvements. Fig. 2 is a similar view, partly in section and showing the handle and jaws in several positions of adjustment. Fig. 3 is a sectional elevation of the main aw with the further flange and cheek-piece in elevation. Fig. 4 is an edge elevation of the wrench. Fig. 5 is a detail perspective of the smaller or supplemental jaw.

Like letters of referencein the several figures indicate the same parts.-

In the particular wrench illustrated the two clamping-jaws A and B are shown with substantially straight gripping-faces having serrations or teeth, as usual but it is obvious that the faces may be made to suit the character of work to be operated upon. The main jaw A is formed with parallel and relatively wide strengthening-flanges A on its rear face, and these flanges are prolonged at an acute angle to the .said jaw to form the parallel side or cheek pieces A the flanges and cheek-pieces merging into each other, thereby afl'ording the most advantageous disposition of the metal to give the greatest possible strength with the minimum weight.

The-edges of the cheek-pieces toward the face of the jaw form parallel guiding and bearing surfaces for the smaller or su plemental j aw but it will be noted that the said surfaces extend at an acute angle with relation to the face of'the jaw. Parallel with the bearing-surfaces a the cheek-pieces are formed with guideways for retaining the smaller j aw in its relation to the cheek-pieces, such guideways being preferably in the form of grooves or channels having a straight outer wall a at substantially right angles to the plane of the cheekpiece and a sloping or inclined wall a which may be at such angle as to allow suflicient metal in the cooperating part of the smaller aw and at the same time form a structure which may be readily cast in simple molds.

The smaller or supplemental aw B is also formed with two parallel flanges B, having bearing-surfaces 1) adapted to slide on the edges of the cheek-pieces and also having projections or guides l) of a similar shape to and adapted to work in the before-mentioned guideways in the cheek-pieces in such manner as to allow the jaws to slide toward and from each other quite freely.

The handle 0 has its end extended in be tween the cheek-pieces and also in between the flanges on the smaller jaw. It is connected with both these parts by pivot pins or bolts. The pivot pin or bolt D connecting the handle and smaller jaw is preferably located approximately midway of the length of the jaw-face, although for some purposes it may be desirable to locate it nearer one end or the other of the jaw.

The arrangement of the main jaw A and cheek-pieces at an acute angle with relation to each other permits of the location of the pivot-pin E connecting the cheek-pieces and handle well forward with relation to the gripping-face of the jaw, whereby an object held between the jaws is not liable to squeeze out, and at the same time by properly locating the pivotpin, as shown, while it is practicable to secure a firm grip there is little danger of crushing a pipe when strain is applied to the handle. Inasmuch as the jaws move in right lines, sufficient play must be left in the pivotal connection for this purpose, and in the present invention this fact is utilized to secure an equalization of the pressure at all points as well as to restrain the tendency of the smaller jaw to tilt in its guides when pressure is applied. The desired results are accomplished by forming a curved hearing or slot F in the handle for the pivot-pin E, said bearing being bowed toward that side of the handle nearest the main jaw. With this construction the pivot-pin travels from the outer to the inner end of the slot and back toward the outer end again during a complete movement of the jaws toward each other. In operation, therefore, when the jaws are wide open, as in full lines, Fig. 2, the pivot-pin acts against the sharply-inclined face of the slot near its end, and any move ment reduces the distance between the pins D and E, causing the small jaw to travel in a straight path and at the same time increases the gripping power. As the jaw moves to the centralposition (indicated in dotted lines) the relative sliding movement of the pivotpin and handle decreases and the handle opcrates as a simple lever of the first order and is at its greatest power as a lever. Then as the jaws are brought still nearer together the pivot-pin travels back in the slot to the second position (indicated in dotted lines) and acts wedgingly to close the jaws, thus equalizing the pressure and making the gripping power throughout the movement sufficient to prevent any slip on the pipe or object to be turned. It will be noted that the distance between the pivot-pins I1 and D is always less than the distance between the center of the work being held and the outer pivotpin D, as it is found that the best results can only be secured when this condition exists. The parts may be held up by a spring of any preferred type-*for instance, as shown at K, where the spring is fastened to the handle readies and bears against the rounded rear part 76 of the jaw and is protected against injury by the ribs or flanges between which it is located.

The wrench is so designed in the preferred construction that the line of gripping pressure between the jaws is always inside of the pivotal connection between the handle and. smaller jaw and outside of the pivotal connection between the handle and main jaw. In other words, the line of gripping pressure is between the pivots, as shown by the dotted line S in Fig. 1, and consequently the pressure tends to bind the smaller jaw against its guiding-surfaces on the cheek-pieces, thereby holding the jaw in and aiding in preventing a crushing strain being brought to bear on the pipe; but the binding or locking tendency is at once relieved if the jaw can advance and only manifests itself under a considerable resistance to the advance of the jaw and when torque is exerted on the object held between the jaws. To prevent small pipe from passing down into the extremity of the acute anglein the main jaw, aproj ection G is formed in the angle, and. this projection may take the form of an edge, which will act as a supplemental tooth, although its primary function is to hold the pipe out in position to be acted on by several of the teeth in the jaws. This construction also facilitates manufacture in that it avoids the necessity of making the teeth close to the angle and strengthens the structure at one of its weakest points.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A wrench embodying a jaw having cheek-pieces extending from one end thereof and having guideways therein formed with straight outer and inclined inner walls, a second jaw having flanges formed with guides conforming to the guideways and adapted to slide on said cheek-pieces toward and from the other aw and a lever-handle pivotally connected with the cheek-pieces and second jaw at different points; substantially as described.

2. A wrench embodying a pair of grippingjaws having cooperating guides for guiding them toward and from each other in right lines, a lever-handle pivotally connected with both of said jawsby pivotal connections movable toward and from each other, the relation of the parts being such that the pivots are in proximity when the jaws are in an in termediate position and more widely separated. when the jaws are closed or open; sub stantially as described.

3. A wrench embodying a gripping-jaw having cheek-pieces with guides thereon extending at an acute angle to the jaw, a second jaw mounted to slide in said guides, a lever-handle pivotally connected with the last-mentioned jaw and having a curved slot located between the cheek-pieces and a pin passing through said slot and mounted in such position in the cheek-pieces that the pivot-pinin the movable jaw will move away from the same during the final portion of the movement of the jaw in both directions; substantially as described.

4. A Wrench embodying jaws guided one by the other to move toward and from each other in right lines, and a lever-handle pivotally connected with one-j aw and pivotally and movably connected with the other jaw, said jaws and pivotal connections being so positioned and rotated that the length of the shorter arm of the lever-handle increases dur- Witnesses:

ALEXANDER S. STEUART, THOMAS DURANT. 

